Our research seeks to understand the mechanisms underlying the perception and production of vocal signals in cotton-top tamarins, as well as the conceptual representations that guide their behavior. We use non-invasive experiments and observation to explore these tropics. In particular, we have used techniques from the fields of ethology, cognitive neuroscience, and cognitive development to address the following questions 1) How do tamarins classify their vocalizations? Is classification determined on the basis of acoustics or on the basis of meaning? 2) Can tamarins lie about the presence of a predator or food? 3) Can tamarins carry out mathematical computations? 4) Do tamarins understand the functional properties of a tool?